Techniques for Reducing Communication Errors in a Wireless Communication System

ABSTRACT

A technique for operating a wireless communication device includes transmitting a scheduling request from the wireless communication device and receiving, following the scheduling request, an uplink grant that assigns an uplink channel to the wireless communication device. A time period between the scheduling request and the uplink grant is determined. Only channel quality information is transmitted in the uplink channel when the uplink grant requests the channel quality information and the time period is less than a predetermined time period.

PRIORITY CLAIM

This application is a continuation of and claims the benefit of priorityfrom U.S. patent application Ser. No. 13/136,486, entitled “Techniquesfor Reducing Communication Errors in a Wireless Communication System”and filed on Aug. 1, 2011, which is a continuation of and claims thebenefit of priority from U.S. patent application Ser. No. 12/052,621,entitled “Techniques for Reducing Communication Errors in a WirelessCommunication System” and filed on Mar. 20, 2008 (issued as U.S. Pat.No. 7,990,919 on Aug. 2, 2011), both of which are fully incorporatedherein by reference for all purposes and to the extent not inconsistentwith this application.

BACKGROUND

1. Field

This disclosure relates generally to a wireless communication systemand, more specifically, to techniques for reducing communication errorsin a wireless communication system.

2. Related Art

Wireless networks that employ third-generation partnership project-longterm evolution (3GPP-LTE) compliant architectures are currently requiredto utilize aperiodic channel quality information (CQI) uplink grantswhen a scheduler (associated with a serving base station (BS)) desiresto schedule a downlink data transmission to a user end (UE) orsubscriber station (SS). The scheduler utilizes CQI reported by the SS(in response to an aperiodic CQI uplink grant) to determine whichportion of a system bandwidth to utilize for a downlink transmission tothe SS. With reference to FIG. 1, a table 100 depicts an examplephysical downlink control channel (PDCCH) format that may be utilized tosignal an uplink grant or a downlink assignment to an SS (from ascheduler via a serving BS) via a PDCCH. As is illustrated, the PDCCHformat includes: a one-bit format field; a one-bit hopping flag field; athirteen-bit resource block (RB) assignment field; a five-bit modulationand coding scheme (MCS) field; a two-bit retransmission sequence number(RSN) field; a two-bit transmit power control (TPC) field; a three-bitcyclic shift for a demodulation reference signal (DMRS) field; a one-bitCQI request field; and a sixteen-bit radio network temporaryidentifier/cyclic redundancy check (RNTI/CRC) field.

A value of the one-bit format field specifies whether a transmission onthe PDCCH is an uplink grant or a downlink assignment. A value of theone-bit hopping flag field specifies whether frequency hopping is turnedon or off and a value of the thirteen-bit RB assignment field specifieswhich RBs are assigned to an SS for uplink or downlink transmissions. Avalue of the five-bit MCS field specifies what MCS is assigned to atransmission. A value of the two-bit RSN field specifies aretransmission sequence and a value of the two-bit TPC field specifies atransmit power level on a physical uplink shared channel (PUSCH). Avalue of the three-bit cyclic shift for DMRS field specifies a cyclicshift for a DMRS and a value of the one-bit CQI request field specifieswhether CQI is requested. Finally, a value of the sixteen-bit RNTI/CRCfield specifies a unique identifier for the SS. A scheduler asserts avalue in the one-bit CQI request field to request CQI from an SS. Aspreviously noted, a scheduler uses a reported CQI to schedule a downlinktransmission for an SS.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and is notlimited by the accompanying figures, in which like references indicatesimilar elements. Elements in the figures are illustrated for simplicityand clarity and have not necessarily been drawn to scale.

FIG. 1 is a diagram of an example physical downlink control channel(PDCCH) format that may be employed to signal an uplink (UL) grant or adownlink (DL) assignment from a scheduler, via a serving base station(BS), to a subscriber station (SS).

FIG. 2 is an example diagram depicting a scheduling request (SR) that istransmitted from an SS and an aperiodic channel quality information(CQI) uplink grant that is transmitted (from a serving BS) to the SSprior to a data uplink grant for the SR due to processing delay.

FIG. 3 is another example diagram depicting an SR that is transmittedfrom an SS and an aperiodic CQI uplink grant that is transmitted from aserving BS prior to a data uplink grant for the SR due to the SR notbeing detected or being deferred.

FIG. 4 is a flowchart of an example communication error reductionroutine, according to the present disclosure.

FIG. 5 is a flowchart of an example communication error reductionroutine, according to one embodiment of the present disclosure.

FIG. 6 is a flowchart of an example communication error reductionroutine, according to another embodiment of the present disclosure.

FIG. 7 is a flowchart of an example communication error reductionroutine, according to yet another embodiment of the present disclosure.

FIG. 8 is a flowchart of an example communication error reductionroutine, according to one aspect of the present disclosure.

FIG. 9 is a flowchart of an example communication error reductionroutine, according to another aspect of the present disclosure.

FIG. 10 is a block diagram of an example wireless communication systemthat may be configured to reduce communication errors according tovarious embodiments of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description of exemplary embodiments of theinvention, specific exemplary embodiments in which the invention may bepracticed are described in sufficient detail to enable those skilled inthe art to practice the invention, and it is to be understood that otherembodiments may be utilized and that logical, architectural,programmatic, mechanical, electrical and other changes may be madewithout departing from the spirit or scope of the present invention. Thefollowing detailed description is, therefore, not to be taken in alimiting sense, and the scope of the present invention is defined onlyby the appended claims and their equivalents. In particular, theembodiments described below may be embodied in various wirelesscommunication devices.

As may be used herein, the term “channel” includes one or moresubcarriers, which may be adjacent or distributed across a frequencyband. Moreover, the term “channel” may include an entire systembandwidth or a portion of the entire system bandwidth. The term,“resource block,” as used herein, includes a number of subcarriers(e.g., twelve subcarriers) which may or may not be adjacent. As is alsoused herein, the term “subscriber station” is synonymous with the terms“user equipment” and “user end,” which include a wireless communicationdevice that may (or may not) be mobile.

A scheduler that is compatible with current LTE agreements schedulesaperiodic feedback of channel quality information (CQI) from asubscriber station (SS) by asserting a CQI request bit in an uplinkgrant transmitted to the SS (in a downlink transmission from a servingBS associated with the scheduler) over a physical downlink controlchannel (PDCCH). For example, if a serving BS has buffered data totransmit to the SS the scheduler may request CQI from the SS todetermine which downlink channel to schedule for a downlink datatransmission to the SS. However, if an SS sends a scheduling request(SR) for a data uplink transmission and a scheduler schedules anaperiodic CQI uplink grant within a predetermined time period (e.g., aprocessing delay time period that corresponds to multiple sub-frames) ofthe SR, the SS may interpret the aperiodic CQI uplink grant as an uplinkgrant for CQI and data (even though the scheduler was unaware of the SRwhen the scheduler scheduled the aperiodic CQI uplink grant). In thiscase, an error condition may occur when the SS sends CQI and data as theserving BS is only expecting CQI.

According to various aspects of the present disclosure, the errorcondition (e.g., attributable to the SS transmitting CQI and data whenthe serving BS is only expecting CQI) may be resolved or avoided bymandating certain scheduler and/or SS behavior. According to oneembodiment of the present disclosure, an SS may be configured todetermine a time period between when an SR was transmitted and an uplinkgrant was received. If the time period is not greater than apredetermined time period (e.g., a time period corresponding to anaverage processing delay, which may include multiple sub-frames) the SSis configured to only transmit CQI in response to the uplink grant (asthe SS assumes that the uplink grant is an aperiodic CQI uplink grant,as contrasted with a data uplink grant that also requested CQI).

According to another embodiment of the present disclosure, an SS may beconfigured to not transmit data and CQI together. As such, when anuplink grant is received, the SS is configured to only transmit CQI (ascontrasted with transmitting both CQI and data) in an uplink channel(associated with the uplink grant) when CQI is requested. The uplinkchannel may, for example, be included in a physical uplink sharedchannel (PUSCH). In the cases above, the serving BS is configured toexpect only CQI in response to an uplink grant that requested CQI (i.e.,an aperiodic CQI uplink grant). According to a different aspect of thepresent disclosure, in order to avoid the error condition (e.g.,attributable to the SS transmitting CQI and data when the serving BS isonly expecting CQI), a scheduler is configured to not schedule a CQIuplink grant within a predetermined time period (e.g., a time periodcorresponding to an average processing delay) of an SR. According toanother aspect of the present disclosure, a serving BS may be configuredto perform blind detection in an uplink transmission following anaperiodic CQI uplink grant to determine whether a received transmissionincludes only CQI (or both CQI and data). As used herein, the term“blind detection” means that a serving BS ascertains whether informationreceived in an assigned uplink channel includes CQI and data or only CQIbased only on the received information.

As noted above, a scheduler can request an aperiodic feedback of CQIfrom an SS. As currently agreed, the aperiodic feedback of CQI isaccomplished in an LTE compliant architecture by using a single bit(i.e., a CQI request bit (see FIG. 1)) in an uplink grant transmitted(via a serving BS) from a scheduler to an SS (via a downlink signal)over a physical downlink control channel (PDCCH). The current PDDCHformat for LTE compliant architectures (see FIG. 1) does not, however,allow the scheduler to request a CQI only feedback. That is, the CQIrequest bit only flags an uplink CQI request and an SS may (or may not)transmit data along with the CQI. For example, assuming that an SS hastransmitted an SR for a data uplink channel allocation and the CQIrequest bit is asserted in a received uplink grant, the SS may transmitboth CQI and data in an uplink channel assigned by the uplink grant. Asnoted above, when a serving BS receives CQI and data (and the serving BSonly expected CQI) packet errors and overhead loss may result.

For example, an error may occur when an SS requests an uplink grant fordata and the scheduler does not have enough resources to allocate to theSS (for some time period) and only allocates an uplink grant after atime delay between which the scheduler schedules an aperiodic CQI uplinkgrant in order to schedule a downlink transmission to the SS. In thiscase, an aperiodic CQI uplink grant may be confused by the SS with anuplink grant for data and CQI. An error may also occur when an SSrequests an uplink grant (for a data transmission) and the uplink grantis not detected by the serving BS, received in error by the serving BS,or is deferred (for various reasons) by the scheduler. In this case, anSS may also confuse an aperiodic CQI uplink grant with an uplink grantfor both CQI and data which results in the serving BS detecting an error(assuming the serving BS is not configured to perform blind detection).

According to various aspects of the present disclosure, the errorcondition (e.g., attributable to the SS transmitting CQI and data whenthe serving BS is only expecting CQI due to non-detection of an SR ordeferred processing of the SR) may be resolved or avoided by mandatingcertain scheduler and/or SS behavior. According to one embodiment of thepresent disclosure, the error condition can be avoided in an LTEcompliant architecture by configuring PDCCH bits so that the schedulercan schedule the SS to transmit CQI only or CQI and data. Specificationof only CQI or CQI and data in an uplink grant can be implemented inconjunction with a CQI request bit by using, for example, one ofthirty-two modulation and coding scheme (MCS) values to indicate a CQIonly request (as not all MCS values are currently used in LTE compliantarchitectures).

In another embodiment, multiple MCS values (each having a differentassociated delay) may be employed to indicate a CQI only request. Forexample, one MCS value may have an associated delay of, for example,four sub-frames and another MCS value may have an associated delay of,for example, eight sub-frames. In either case, an SS is configured todelay transmission of CQI an amount that is associated with the MCSvalue. Alternatively, an additional CQI request bit (or bits) may beemployed to indicate whether an uplink grant is for only CQI or CQI anddata. Values associated with the additional CQI request bit (or bits)may also have different associated delays. It should be appreciated thatdifferent fields, other than the MCS field, may be reused according tothe present disclosure to clearly signal whether an uplink grant is foronly CQI or CQI and data.

The disclosed techniques are contemplated to be applicable to systemsthat employ either orthogonal frequency division multiplex (OFDM) orsingle-carrier frequency division multiple access (SC-FDMA) signaling onuplink and/or downlink channels. A transmitter of an SS or serving BSmay implement one of a phase shift keying (PSK), a quadrature amplitudemodulation (QAM), or other data modulation scheme, depending upon whichmodulation scheme is scheduled. It should be appreciated that any of thevarious PSK, e.g., pi/2 BPSK, QPSK and 8-PSK, or QAM, e.g., 16-QAM and64-QAM, modulation techniques may be implemented in a wirelesscommunication system constructed according to the present disclosure.

According to another embodiment of the present disclosure, a techniquefor operating a wireless communication device includes transmitting ascheduling request from the wireless communication device and receiving,following the scheduling request, an uplink grant that assigns an uplinkchannel to the wireless communication device. Only channel qualityinformation is transmitted in the uplink channel when the uplink grantrequests the channel quality information. In another embodiment, whenthe uplink grant does not request the channel quality information, onlydata is transmitted in the uplink channel.

According to one embodiment of the present disclosure, a technique foroperating a wireless communication device includes transmitting ascheduling request from the wireless communication device and receiving,following the scheduling request, an uplink grant that assigns an uplinkchannel to the wireless communication device. A time period between thescheduling request and the uplink grant is determined. Only channelquality information is transmitted in the uplink channel when the uplinkgrant requests the channel quality information and the time period isless than a predetermined time period.

According to yet another embodiment of the present disclosure, atechnique for operating a wireless communication device includestransmitting a scheduling request from the wireless communication deviceand receiving, following the scheduling request, an uplink grant thatassigns an uplink channel to the wireless communication device. One ormore fields in the uplink grant are then decoded. Only the channelquality information is transmitted in the uplink channel when the one ormore decoded fields specify that only the channel quality information isto be transmitted in the uplink grant.

According to one aspect of the present disclosure, a technique foroperating a wireless communication device includes receiving, at a firstwireless communication device, a scheduling request from a secondwireless communication device. A channel quality information uplinkgrant, which assigns an uplink channel to the second wirelesscommunication device, is then scheduled for the second wirelesscommunication device at least a predetermined time period after thescheduling request. The first wireless communication device thentransmits the scheduled channel quality information uplink grant.

According to another aspect of the present disclosure, a technique foroperating a wireless communication device includes receiving, in anassigned uplink channel, a transmission in response to an uplink grant.The transmission is then decoded to determine whether the transmissionincludes only channel quality information or the channel qualityinformation and data.

According to a different aspect of the present disclosure, a techniquefor operating a wireless communication device includes encoding, at afirst wireless communication device, one or more fields in an uplinkgrant (which assigns an uplink channel to the second wirelesscommunication device) for a second wireless communication device. Thefirst wireless communication device transmits the uplink grant. Onlychannel quality information is received in the uplink channel when theone or more encoded fields specified that only the channel qualityinformation was to be transmitted in the uplink grant.

With reference to FIG. 2, an example communication diagram 200illustrates an example communication sequence between an SS and ascheduler associated with a serving BS. In the example communicationsequence, an SR is transmitted from the SS to the scheduler when the SSwishes to transmit data on an uplink channel. As is illustrated, due toprocessing delay, an aperiodic CQI uplink grant is transmitted prior toa data uplink grant. In this case, the SS may mistake the CQI uplinkgrant for a data uplink grant (that also requests CQI) and transmit bothCQI and data to the serving BS in the CQI uplink grant. As the servingBS is only expecting CQI in the CQI uplink grant (and in the event thatthe serving BS is incapable of correctly decoding both CQI and data), acommunication error is detected in a conventional wireless communicationsystem that requires retransmission. However, in a wirelesscommunication system configured according to the present disclosure, thecommunication error is avoided by proper configuration of the schedulerand/or the SS.

With reference to FIG. 3, an example communication diagram 300illustrates an example communication sequence between an SS and ascheduler associated with a serving BS. In the example communicationsequence, an SR is transmitted from the SS to the scheduler when the SSwishes to transmit data on an uplink channel. As is illustrated, due tothe SR not being detected (or the SR being deferred due to, for example,lack of network capacity), an aperiodic CQI uplink grant is transmittedprior to a data uplink grant for the SR. In this case, the SS may alsomistake the CQI uplink grant for a data uplink grant (that also requestsCQI) and transmit both CQI and data to the serving BS in the CQI uplinkgrant. As the serving BS is only expecting CQI in the CQI uplink grant(and in the event that the serving BS is incapable of correctly decodingboth CQI and data) a communication error is also detected in aconventional wireless communication system that requires retransmission.However, in a wireless communication system configured according to thepresent disclosure, the communication error is also avoided by properconfiguration of the scheduler and/or the SS.

Turning to FIG. 4, an example communication routine 400 is depicted thatis configured to reduce communication errors in a wireless communicationsystem according to one aspect of the present disclosure. The routine400, which may be employed in an SS, is initiated at block 402, at whichpoint control transfers to block 404. In block 404, the SS transmits anSR for an uplink channel allocation to a scheduler. Next, in block 406,the SS receives an uplink grant from the scheduler (e.g., via a servingBS). Then, in decision block 408, the SS determines whether the uplinkgrant requests CQI. For example, with reference to FIG. 1, the SS maydecode a CQI request bit to determine whether CQI is requested. If CQIis requested in block 408 control transfers to block 410, where the SStransmits only CQI in an assigned uplink channel. If CQI is notrequested in block 408 control transfers to block 412, where the SStransmits only data in the assigned uplink channel. In this manner,communication errors are avoided in that data and CQI are nottransmitted in a same uplink channel allocation. It should beappreciated that constraining a system such that data and CQI are notsent together may reduce overall efficiency of a system in certain cases(as a data uplink grant with a CQI request may be interpreted as anaperiodic CQI uplink grant). Following blocks 410 and 412, controltransfers to block 414 where control returns to a calling routine.

With reference to FIG. 5, an example communication routine 500 isillustrated that is configured to reduce communication errors in awireless communication system according to another aspect of the presentdisclosure. The routine 500, which may be employed in an SS, isinitiated at block 502, at which point control transfers to block 504.In block 504, the SS transmits a scheduling request (SR) for an uplinkchannel allocation to a serving BS. Next, in block 506, the SS receivesan uplink grant from a scheduler (associated with the serving BS). Then,in decision block 508, the SS determines whether a time period betweenthe SR and the uplink grant is less that a threshold time period. In atypical case, the threshold time period corresponds to a processingdelay time.

If the time period is less than the threshold in block 508, controltransfers to block 510 where the SS transmits only CQI in an assigneduplink channel. If the time period is not less than the threshold inblock 508 control transfers to block 512, where the SS transmits CQI anddata in the assigned uplink channel. In this manner, communicationerrors associated with processing delay may be avoided as data and CQIare not transmitted in an uplink channel associated with an aperiodicCQI uplink grant. It should be appreciated that if an SR is not detected(or is deferred by a scheduler), a communication error may not beavoided when the time between transmitting the SR and receiving theuplink grant are greater than the threshold time period (as an aperiodicCQI uplink grant may be received more than a threshold time period afteran SR, but prior to a data uplink grant that also requests CQI).Following blocks 510 and 512, control transfers to block 514 wherecontrol returns to a calling routine.

With reference to FIG. 6, an example communication routine 600 isdepicted that is configured to reduce communication errors in a wirelesscommunication system according to yet another aspect of the presentdisclosure. The routine 600, which may be employed in an SS, isinitiated at block 602, at which point control transfers to block 604.In block 604, the SS transmits an SR for an uplink channel allocation toa serving BS. Next, in block 606, the SS receives an uplink grant from ascheduler (e.g., via the serving BS). Then, in block 608, the SS decodesone or more fields in the uplink grant. For example, the SS may decode abit in a one-bit CQI request field and five bits in an MCS field todetermine if only CQI or CQI and data are scheduled for an uplinkchannel associated with the uplink grant.

Next, in decision block 610, the SS determines whether the decodedfield(s) indicate that CQI only is to be transmitted in the uplinkchannel. If the decoded field(s) indicate only CQI, control transfersfrom block 610 to block 612, where the SS transmits only CQI in anassigned uplink channel. If the decoded field(s) indicate CQI and data,control transfers from block 610 to block 614, where the SS transmitsCQI and data in the assigned uplink channel. In this manner,communication errors associated with processing delay may be avoided aseach uplink grant specifically signals whether an associated uplinktransmission should include only CQI or CQI and data. Following blocks612 and 614, control transfers to block 616 where control returns to acalling routine.

Turning to FIG. 7, an example communication routine 700 is illustratedthat is configured to reduce communication errors in a wirelesscommunication system according to another aspect of the presentdisclosure. The routine 700, which may be employed in a serving BS, isinitiated at block 702, at which point control transfers to block 704.In block 704, a scheduler (associated with the serving BS) receives anSR for an uplink channel allocation from an SS. Next, in block 706, thescheduler schedules an aperiodic CQI uplink grant (for the SS) at leasta predetermined time period after the SR. In a typical case, thepredetermined time period corresponds to a time period that is greaterthan a typical processing delay time for providing a data uplink grant(with or without CQI) in response to the SR. Next, in block 708, theserving BS (which is associated with the scheduler) transmits the CQIuplink grant (in a typical case, after transmitting a data uplink grantfor the SR). It should be appreciated that if an SR is deferred by thescheduler, a communication error may still be avoided by delayingtransmission of the CQI uplink grant for the SS until after transmittingthe data uplink grant (for the SR) to the SS. Following block 708,control transfers to block 710 where control returns to a callingroutine.

With reference to FIG. 8, an example communication routine 800 isillustrated that is configured to reduce communication errors in awireless communication system according to still another aspect of thepresent disclosure. The routine 800, which may be employed in a servingBS, is initiated at block 802, at which point control transfers to block804. In block 804, the scheduler receives (via the serving BS) atransmission in response to an uplink grant. Next, in block 806, theserving BS decodes, e.g., using blind decoding, the transmission todetermine if the transmission includes only CQI or CQI and data. In thismanner, communication errors associated with receiving both CQI and datawhen only CQI was expected may be avoided, as the serving BS isconfigured to decode the transmission and ascertain the content of thetransmission (i.e., whether the transmission include only CQI or CQI anddata). Following block 806, control transfers to block 808 where controlreturns to a calling routine.

With reference to FIG. 9, an example communication routine 900 isillustrated that is configured to reduce communication errors in awireless communication system according to another embodiment of thepresent disclosure. The routine 900, which may be (at least partially)employed in a serving BS, is initiated at block 902, at which pointcontrol transfers to block 904. In block 904, the serving BS encodes oneor more fields in an uplink grant. For example, the serving BS mayencode a bit in a one-bit CQI request field and five bits in an MCSfield to indicate if only CQI or CQI and data are scheduled for anuplink channel associated with the uplink grant. Next, in block 906, theserving BS transmits the uplink grant. Then, in decision block 908, theserving BS receives an uplink communication from the SS (in response tothe uplink grant) and (based on how the serving BS encoded the fields)determines whether a received uplink communication includes only CQI. Ifonly CQI was supposed to be transmitted from the SS (according to theencoded fields), control transfers from block 908 to block 910, whereonly CQI is processed. If CQI and data was supposed to be transmittedfrom the SS (according to the encoded fields), control transfers fromblock 908 to block 912, where CQI and data are processed. Followingblocks 910 and 912, control transfers to block 914 where control returnsto a calling routine.

With reference to FIG. 10, an example wireless communication system 1000is depicted that includes a plurality of subscriber stations or wirelessdevices 1002, e.g., hand-held computers, personal digital assistants(PDAs), cellular telephones, etc., that may implement communicationlinks according to one or more embodiments of the present disclosure. Ingeneral, the wireless devices 1002 include a processor 1008 (e.g., adigital signal processor (DSP)), a transceiver 1006, and one or moreinput/output devices 1004 (e.g., a camera, a keypad, display, etc.),among other components not shown in FIG. 10. As is noted above,according to various embodiments of the present disclosure, techniquesare disclosed that reduce communication errors by configuring ascheduler and/or an SS according to various disclosed techniques. Thewireless devices 1002 communicate with a base station controller (BSC)1012 of a base station subsystem (BSS) 1010, via one or more basetransceiver stations (BTS) 1014, to receive or transmit voice and/ordata and to receive control signals. The BSC 1012 may, for example,employ a scheduler for scheduling uplink grants and downlink assignmentsto each of the wireless devices 1002. In general, the BSC 1012 may alsobe configured to choose a modulation and coding scheme (MCS) for each ofthe devices 1002, based on channel conditions.

The BSC 1012 is also in communication with a packet control unit (PCU)1016, which is in communication with a serving general packet radioservice (GPRS) support node (SGSN) 1022. The SGSN 1022 is incommunication with a gateway GPRS support node (GGSN) 1024, both ofwhich are included within a GPRS core network 1020. The GGSN 1024provides access to computer(s) 1026 coupled to Internet/intranet 1028.In this manner, the wireless devices 1002 may receive data from and/ortransmit data to computers coupled to the Internet/intranet 1028. Forexample, when the devices 1002 include a camera, images may betransferred to a computer 1026 coupled to the Internet/intranet 1028 orto another one of the devices 1002. The BSC 1012 is also incommunication with a mobile switching center/visitor location register(MSC/VLR) 1034, which is in communication with a home location register(HLR), an authentication center (AUC), and an equipment identityregister (EIR) 1032. In a typical implementation, the MSC/VLR 1034 andthe HLR, AUC, and EIR 1032 are located within a network and switchingsubsystem (NSS) 1030, which performs various functions for the system1000. The SGSN 1022 may communicate directly with the HLR, AUC, and EIR1032. As is also shown, the MSC/VLR 1034 is in communication with apublic switched telephone network (PSTN) 1042, which facilitatescommunication between wireless devices 1002 and land telephone(s) 1040.

As used herein, a software system can include one or more objects,agents, threads, subroutines, separate software applications, two ormore lines of code or other suitable software structures operating inone or more separate software applications, on one or more differentprocessors, or other suitable software architectures.

As will be appreciated, the processes in preferred embodiments of thepresent invention may be implemented using any combination of computerprogramming software, firmware, or hardware. As a preparatory step topracticing the invention in software, the computer programming code(whether software or firmware) according to a preferred embodiment willtypically be stored in one or more machine readable storage mediums suchas fixed (hard) drives, diskettes, optical disks, magnetic tape,semiconductor memories such as read-only memories (ROMs), programmableROMs (PROMs), etc., thereby making an article of manufacture inaccordance with the invention. The article of manufacture containing thecomputer programming code is used by either executing the code directlyfrom the storage device, by copying the code from the storage deviceinto another storage device such as a hard disk, random access memory(RAM), etc., or by transmitting the code for remote execution. Themethod form of the invention may be practiced by combining one or moremachine-readable storage devices containing the code according to thepresent invention with appropriate standard computer hardware to executethe code contained therein. An apparatus for practicing the inventioncould be one or more computers and storage systems containing or havingnetwork access to computer program(s) coded in accordance with theinvention.

Although the invention is described herein with reference to specificembodiments, various modifications and changes can be made withoutdeparting from the scope of the present invention as set forth in theclaims below. For example, many of the techniques disclosed herein arebroadly applicable to a variety of reference signals employed inwireless communication systems. Accordingly, the specification andfigures are to be regarded in an illustrative rather than a restrictivesense, and all such modifications are intended to be included with thescope of the present invention. Any benefits, advantages, or solution toproblems that are described herein with regard to specific embodimentsare not intended to be construed as a critical, required, or essentialfeature or element of any or all the claims.

Unless stated otherwise, terms such as “first” and “second” are used toarbitrarily distinguish between the elements such terms describe. Thus,these terms are not necessarily intended to indicate temporal or otherprioritization of such elements.

What is claimed is:
 1. An apparatus for operating a wirelesscommunication device, comprising: a transceiver; and a processor coupledto the transceiver and configured for: transmitting a scheduling requestfrom the wireless communication device; receiving, following thescheduling request, an uplink grant that assigns an uplink channel tothe wireless communication device; determining a time period between thescheduling request and the uplink grant; and transmitting only channelquality information in the uplink channel when the uplink grant requeststhe channel quality information and the time period is less than apredetermined time period.
 2. The apparatus of claim 1, wherein theprocessor is further configured for: transmitting the channel qualityinformation and data in the uplink channel when the uplink grantrequests the channel quality information and the time period is greaterthan the predetermined time period.
 3. The apparatus of claim 1, whereinthe uplink grant is an aperiodic channel quality information uplinkgrant.
 4. An apparatus for operating a wireless communication device,comprising: a transceiver; and a processor coupled to the transceiverand configured for: receiving, at a first wireless communication device,a scheduling request from a second wireless communication device;scheduling a channel quality information only uplink grant for thesecond wireless communication device at least a predetermined timeperiod after the scheduling request, wherein the channel qualityinformation uplink grant assigns an uplink channel to the secondwireless communication device; and transmitting, from the first wirelesscommunication device, the scheduled channel quality information uplinkgrant.
 5. An apparatus for operating a wireless communication device,comprising: a transceiver; and a processor coupled to the transceiverand configured for: encoding, at a first wireless communication device,one or more fields in an uplink grant for a second wirelesscommunication device, wherein the uplink grant assigns an uplink channelto the second wireless communication device; transmitting, from thefirst wireless communication device, the uplink grant; receiving onlychannel quality information in the uplink channel when the one or moreencoded fields specified that only the channel quality information betransmitted in the uplink grant; and receiving the channel qualityinformation and data in the uplink channel when the one or more encodedfields specified that the channel quality information and the data betransmitted in the uplink grant.
 6. The apparatus of claim 5, whereinthe one or more decoded fields include a single channel qualityinformation request field that includes multiple bits, wherein themultiple bits indicate whether the channel quality information isrequested and whether only the channel quality information or thechannel quality information and the data can be transmitted in theuplink grant.
 7. The apparatus of claim 5, wherein the one or moredecoded fields include a channel quality information request field thatincludes one bit that indicates whether the channel quality informationis requested and a modulation and coding scheme field whose valueindicates whether only the channel quality information or the channelquality information and the data can be transmitted in the uplink grant.8. A computer-program storage apparatus for operating a wirelesscommunication device comprising a memory having one or more softwaremodules stored thereon, the one or more software modules beingexecutable by one or more processors and the one or more softwaremodules comprising: code for transmitting a scheduling request from thewireless communication device; code for receiving, following thescheduling request, an uplink grant that assigns an uplink channel tothe wireless communication device; code for determining a time periodbetween the scheduling request and the uplink grant; and code fortransmitting only channel quality information in the uplink channel whenthe uplink grant requests the channel quality information and the timeperiod is less than a predetermined time period.
 9. The computer-programstorage apparatus of claim 8, the one or more software modules furthercomprising: code for transmitting the channel quality information anddata in the uplink channel when the uplink grant requests the channelquality information and the time period is greater than thepredetermined time period.
 10. The computer-program storage apparatus ofclaim 8, wherein the uplink grant is an aperiodic channel qualityinformation uplink grant.